Throttling device for two opposed



July 8, 1947. RAFTER 2,423,727

THROTTLING DEVICE FOR TWO OPPOSED ELECTRICALLY CONTROLLED FORCES FiledNOV. 13, 1945 2 Sh eetsSheet l F RELAY V 4 a? 1 M F g9 27 JF----- 30 mRELAY U 2 h INVENT (75% 72:040/ Ear 6/ ATTORNEYS J. R. RAFTER July 8,1947.

v THROTTLING DEVICE FOR TWO OPPOSED ELECTRICALLY CONTROLLED FORCES 2Sheets-Sheet 2 Filed NOV. 13, 1945 Patented July 8, 1947 THROTTLINGDEVICE FOR TWO OPPOSED ELECTRICALLY CONTROLLED FORCES John RichardRafter, Sharon, Mass, assignor to Providence Braid Company, acorporation of Rhode Island Application November 13, 1945, Serial No.628,193

9 Claims.

This invention relates to a throttling device for two electricallyopposed forces, such for instance as a heating source and a cold sourceor a humidifying source and a dehumidifying source or similar opposedequipment.

Heretofore in the control of two opposing forces, such as heating andcooling, it has been necessary with the apparatus which is in use tooperate the heating source or the cooling source so that either one orthe other was operating. In many instances, it is unnecessary, due tothe natural condition, such for instance, as the temperature of the air,that one or the other of these be operating. For instance, should theroom temperature be desired to be controlled and the outside temperaturewas nearly the same as thetemperature in the room, considerable waste ofenergy would occur ifone of the two forces is always operating as aneutral period could be utilized to advantage. However, the controlswhich are now in existence do not permit of such operation. Where camsare used, it is customary to use one portion of the cam during arevolution to operate one of the forces while the other force isoperated during the remainder of the operation of the cam.

One of the objects of this invention is to provide an arrangement sothat but one of the opposing forces is operated at a time, rather thanalternation of operation between the two.

Another object ofthis invention is to provide the electrical control ofthe two forces so that each may be controlled inan off and on manner fora certain portion of the cycle of operation of the controlling unit.

Another object of this invention is to so provide individual electricalcontrols that dissimilar action of the two control may be had, and thusa closer control of the ultimate result provided.

Another object of the invention is to provide a control so that shouldnatural conditions supply the desired result in a certain area the powerneed not be utilized for alternately supplying the opposed forces toneutralize one another and thus arrive at the desired result.

Another object of this invention is to provide a control so that each ofthe forces may be progressively increased or decreased throughout therange of their operation.

Another object. of this invention is to provide an adjustment throughwhich the forces may. be

controlled.

Another object of this invention is to provide a bypass for suchadjustment to speed up theop- 2 eration, should extreme changes berequired of the system which is to be controlled.

With these and other objects in view, the invention consists'of certainnovel features of construction, aswill be more fully described andparticularly pointed out in the appended claims.

In the accompanying drawings:

Fig. 1 is a plan view of the apparatus of this invention;

Fig. 2 is an elevation of the apparatus;

Fig. 3 is a perspective view of a portion of the constantly rotatingshaft with a cam surface thereon;

Fig. 4 is a section on substantially line 4-4 of Fig. 2;

Fig. 5 is a diagrammatic view illustrating the wiringcircuits of theapparatus.

In proceeding with this invention I provide a constantly driven shafthaving raised cam-like surfaces thereon for engaging and operating anelectric switch. The electric switch is carried by a reciprocating riderand may be moved in one direction orthe'other so as to cause the switchto be closed or opened varying amounts of time. The two cam surfaces maybe different and one control one opposing force and the other controlthe other opposing force so that the controlled forces may respondaccording to the characteristics of the cam. The rider also carriesanother switch which -will shift so as to place one of two circuits inconnection with the switch carried by the rider dependent upon theposition of the rider along the shaft upon which it operates, thusthrough substantially one part of the movement of the rider one forcesuch as heat may be actuated while through another portion of themovement of the rider the other force such as cold may be actuated. Therider may be conveniently threaded and the shaft on which it operatesthreaded with the control through a reversible electric motor. This is avery convenient operation which will respond to a thermostat whichmaycall for heating or call for cooling. from either a heatingunit or acooling unit. An overall adjustable control for the operation of'therider may be provided which may be removed from the constantly operatedcam shaft.

With reference to the drawings, which for illustrative purposes only isshown as applied to a temperature control, I have shown a mountingsupport or base l0 which has suitable frame work II and [2 providingbearings for two rotating shaft .and two stationary shafts. There is acamshaft M which is constantly driven by an electric motor 15 throughthe worm is and worm gear H on the end of the shaft l4. Shells I8 areslidable over the shaft l4 and are fixed thereto which provide raisedsurfaces IS with edges 28. Two of these shells l8 and I8 are providedwhich progressively increase from an intermediate point on the shafttoward the ends thereof. The arrangement is such that when an armengages the shaft, it will be raised by one of these surfaces for aperiod dependent upon the rotary angular distance or are, at rightangles to the axis of the shaft of such surface, while at the saidintermediate point of the shaft the arm will not be raised because ofthe space between these cam surfaces.

A second shaft 2| is threaded throughout its length and is rotatablysupported in the frames l and I2. This shaft is driven from a reversibleelectric motor 22 by the train of gearing 23, 24; shaft 25 with worm 26thereon and worm gear 21. A rider 28 having a threaded bore is mountedon this shaft and may be moved axially of the shaft in one direction orthe other dependent upon the direction of rotation of the motor 22. Thismotor is actuated in response to a thermostat in the room which is to becontrolled as will be more fully explained in connection with thedescription of the wiring diagram of the apparatus. On this rider 28 amicroswitch 29 is carried which has an operating arm 30 with a roll 3|at its end to roll upon the surface of the shaft I4 and on the camsurfaces l9 or l9 which are carried thereby. This microswitch functionsin two circuits, one of which goes to the heating unit and the other ofwhich goes to the cooling units as will be more fully described. Whenthe roller 3| rides upon the cam surface l9, it will be raised for thelength of time that the raised surface is in engagement with this rollerand then it will drop back to the surface of the shaft l4 and traveltherealong with the microswitch open.

The third shaft or rod is designated 32 and is carried by the frame workH and I2. It consists of a cylindrical rod of two diameters, the largerdiameter being designated 33 and extending for the length of one cam l9while the smaller diameter is designated 34 and extends for the lengthof the cam IS. A second microswitch 35 of the single pole, double throwtype, is carried by the rider and is provided with an arm 36 having aroller 3'! which will rest upon either the portion 34 or the portion 33of the rod or guide 32. When the roller is in engagement with theportion 34, its switch arm will be against one pole, whereas when inengagement with the portion 33 the switch arm will be engaged with theopposite pole. This places in circuit either the heating unit or thecooling unit, dependent upon the position of the switch arm inengagement with one pole or the other. In order to limit the operationof the reversing motor, I also utilize limit switches 38 at one end and38 at the other end so that arms 40 and 4| will engage either one or theother of these limit switches as the rider approaches the end of itstravel so as to disconnect the energizing circuit to the reversiblemotor 32 and stop the axial movement of the rider.

In order to further control the time of operation of the reversiblemotor for any portion of the cycle of operation of the constant speedshaft M, I have inserted a switch 43 in the common line to thereversible motor 22 so that the switch may be moved along the arm 44 andheld in place by the bolt 45, thus, its arm 48 may engage 4 the raisedsurface |8 to close the switch for only that portion of rotation thatthe arm is in engagement with the surface |9 during the cycle ofoperation of the shaft l4.

In considering the operation of the apparatus (see Fig. 5), we willassume that the temperature of a room is desired to be controlled, thatwe have a source of heat so that hot air may be supplied in the room anda refrigerating source so that cold air may be supplied to the room, itbeing desired to maintain this room at a certain given temperature. Athermostat will have one pole or contact 58 which may be engaged by anarm 5| when the room is too hot and cooling is called for. There mayalso be a contact 52 which. may be engaged by the arm 5| when the roomis too cool and heating is called for. A common lead 53 may extend fromthe thermostat in order to complete the electric circuits from thecontacts 58 and 52. Thi common terminal 53 is connected by a lead 54through the contact 55 of the adjusting switch 43, the contact arm 56 ofwhich is controlled by the operating arm 46 while the other end of thiscontact arm extends from the contact 51 through lead 58 to the commonpole 58 of the reversing motor 22. The electric circuit from the contact52 is through line 60 through limit switch 39 by connecting to the pole6| thereof, thence through the arm 62 of the switch to the contact 63and thence to the terminal 64 of the reversing motor 22 through lead 65.The reversing motor will so turn the second shaft 2| as to cause therider to move to the right when heating is called for and the limitswitch will limit the movement of thi rider as above explained. Ifcooling is called for, the circuit is completed to the reversible motorfrom the contact 58 through the line 66 and through the limit switch 38by connection at contact 61 thence through arm 68 to contact 69 andthence through line 18 to the connection 1| on the reversing motor 22.The reversing motor when operated through this last named circuit willcause the rider to move to the left as shown in Fig. 5 which wouldengage the limit switch 38 and limit the rider on this part of the shaftwhen cooling would be called for. In the position in which the rider isshown in Fig. 5 the arm 36 engages the small portion 34 of the rod 32and the microswitch 35 will cause the contact arm 12 to be in engagementwith the contact 4 l3 and also through lead 74 will connect to thecooling control designated generally 15. This lead is to the terminal 16of the relay coil 11 thereof and leaves this relay coil through contactl8 thence through line 18 and to the transformer 8|. From the other sideof the transformer circuit is established through lead 82 to the contact83 thence through contact arm 84 of the microswitch 29 and from contact85 of this microswitch through line 86 to the contact 8'! of themicroswitch 35, which completes the circuit to the cooling controlthrough both microswitches 29 and 35, both carried by the rider 28. Thecooling unit will be in operation for the length of time that the arm 30is on the raised portion I8 of the shaft l4. The reversible motor willbe carrying the rider to the left as cooling is called for through suchportion of the operation of the shaft l4 as is permitted by the controlof microswitch 43. Thus, the duration of the operation of the coolingapparatus will be gradually increased until such time as the roomarrives at the desired temperature when the thermostat will leave thecontact 50.

If we now assume that the room has become too cool, then the thermostatarm will switch to contact 52 which will call for heating and thereversible motor will be operated so as to move the rider to the right.As this movement commences, the cooling will become less and less due tothe location of the rider at a point where the arm 30 will engage thedecreasing portion of cam IQ of the shaft 34. This will continue withless supplying of cool air until a point when the arm 30 of themicroswitch 29 arrives at a point between the two cams l9 and [9' whenneither heating nor cooling unit will operate.

If heating is still further called for, then the rider is moved furtherto the right as it passes between the cams of the layout the arm 36 willengage the larger portion 33 of the shaft 32 and throw the double throwswitch so that the arm I2 will engage th contact 90 of this switch andat the same time the arm 30 with its roller 3| will engage the camsurface I!) of the shaft I 4 for such portion of the rotation of the camas the high part of surface i9 is beneath the arm 30. In this case thecircuit from the contact 99 is through the lead 9i to the terminal 92 ofthe heating unit 93 which connects in circuit th relay coil 94 and fromterminal 95 thereof, through lead 96, the circuit is completed to thetransformer 8|. The return from the transformer 8| is through thecircuit previously traversed which includes the lead 82, contact 83 ofmicroswitch 29, arm 84 thereof, contact 85 and lead 86 to themicroswitch 35, thence through contact 8'! to arm 12 which is, in thisinstance, in engagement with the contact or pole 90 thereof.

In some instances it might be desirable to bypass the adjustablypositioned microswitch Z3 and to do this a thermostat 91 having contactswhich are outside of the limits of the usual contacts is provided asshown in Fig. 5. This 1100K- up is such that leads 93 and 99 extend fromthe leads 54 and 58 and these are bridged by a contact I00 if a certainheight of temperature is attained while if the temperature drops theleads are bridged by a contact IOI each in response to movement of abimetal member.

I claim:

1. A throttling device for two opposed electrically controlled forcescomprising a constant speed shaft, switch actuating surfaces on saidshaft, a. threaded shaft, a rider actuated thereby to movelongitudinally along said constant speed shaft, a switch carried by saidrider to be actuated by said actuating surfaces, a pair of circuits bothincluding said switch and means ineluding a switch carried by said riderto complete one or the other of said pair of circuits dependent on theposition of said rider along said threaded shaft.

2. A throttling device for two opposed electrically controlled forces,comprising a constantly rotating shaft, a pair of cams comprisingrelatively raised surfaces on said shaft increasing progressively inopposite directions from a point intermediate the ends of the shaftoutwardly toward the ends, a second shaft, a rider thereon carrying aswitch to engage said raised surfaces 0 Number and be closed thereby fora length of time dependent upon the position of the rider relative tothe constant speed shaft, and means to move the rider along said secondshaft.

3. A throttling device for two opposed electrically controlled forcescomprising a constantly rotating shaft, a pair of cams comprisingrelatively raised surfaces on said shaft increasing progressively inopposite directions from a point intermediate the ends of the shaftoutwardly towards the ends, a second shaft, a rider thereon carrying aswitch to engage said raised surfaces and be closed thereby for a lengthof time dependent upon the position of the rider relative to theconstant speed shaft, and means to move the rider along said secondshaft, a pair of circuits having a common portion including said switchand means to shift said switch from one circuit to the other as saidrider moves said switch from one cam to the other.

4. A throttling device as set forth in claim 3 wherein said meansincludes a double throw switch carried by said rider.

5. A throttling device as set forth in claim 3 wherein said meansincludes a, single pole double throw switch carried by said rider and aguide surface for actuating said switch.

6. A throttling device as set forth in claim 3 wherein said second shaftis threaded and a reversible motor rotates said shaft in either onedirection or the other.

7. A throttling device as set forth in claim 3 wherein said second shaftis threaded and a. reversible motor rotates said shaft in either onedirection or the other and a switch actuated by one of said cam surfacesdetermines the length of time said motor shall operate.

8. A throttling device as set forth in claim 3 wherein said second shaftis threaded and a reversible motor rotates said shaft in either onedirection or the other and means are provided to limit the length ofmovement of said rider in one direction or the other.

9. A throttling device for two opposed electrically controlled forcescomprising a constant speed shaft, switch actuating surfaces on saidshaft, a threaded shaft, a rider actuated thereby to move longitudinallyalong said constant speed shaft, a switch carried by said rider to beactuated by said actuating surfaces, a pair of circuits both includingsaid switch, and a second switch actuating longitudinally extendingsurface and another switch carried by said rider having an arm to movealong said second surface to complete one or the other of said pairs ofcircuits dependent upon the portion of the second surfacesaid armengages.

JOHN RICHARD RAFIER.

REFERENCES CITED UNITED STATES PATENTS Name Date 1,461,001 Hartford July3, 1923

